Signal encoder selector



March 2, 1965 c. E. DE PUY 3,172,099 SIGNAL ENcoDER SELECTOR Filed Jan. 16. 1961 4 Sheets-Sheet l 'whims- IN VEN TOR.' QAM/Vc; www wf ATTORNEYS March 2, 1965 c. E. DE PUY 3,172,0 99

SIGNAL ENCODER SELECTOR Filed Jan. 16, 1961 4 Sheets-Sheet 2` ATTORNEYS March 2, 1965 c. E. DE PUY SIGNAL ENcoDER SELECTOR 4 Sheets-Sheet 3 Filed Jan. 16, 19,61

ewa/JM A T7 ORNE YS March 2, 1965 Filed Jan. 16. 1961 C. E. DE PUY SIGNAL ENCODER SELECTOR 4 Sheets-Sheet 4 l il@ 3423:

INVENTOR. (L AHA/f! 0W/120 w United States Patent O 3,172,099 SIGNAL ENCODER SELECTOR Clarence Edward De Puy, San Francisco, Calif., assignor to Secode Corporation, a corporation of California Filed Jan. 16, 1961, Ser. No. 82,750 Claims. (Cl. 340-365) This invention relates in general to a selective signal receiving and sending device and more particularly to a device capable of sending and receiving a coded electrical signal.

The transmission of information over an electrical communication media by coded pulses has been long known in the art. Generation of these coded pulses has been accomplished by various means; for instance, motor driven cam operated contacts have been commonly used in automatic station identifiers to provide a train of coded pulses. In all previous systems where code generation and code receiving or decoding was required, separate means to accomplish these functions were used.

It has always been possible to combine a selector and a pulse generator making use of certain common hardware in circuit elements, but little advantage was to be gained since in many cases the coded pulses to be sent out differed from the incoming pulses, which required separate memory element or code cams. Many new problems arose with the advent of two-way radio as applied to telephone cornmunication. Clearly the radio communication channel is unlike the telephone line in that the parties are not identifiable by being on a specific line. Itis, therefore, necessary in such a system to use some scheme whereby the individual party may be recognized by the supervisory control system in the central oflice. 'Since each individual party already has a unique call or station number assignment the same number may be used to identify the party when he is initiating or ending a call. Recognition of this fact and the fact that a single memory device is required at the party station to store the party number for both selective decoding incoming supervisory signals and generation of outgoing signals is the key to the scheme and embodiments which are herein disclosed.

The foregoing two paragraphs outline the features and vfunctions essential to the preferred embodiment of this invention, but it is also possible to use the structure hereinafter described for purposes of sending signals, even though it is not elected also to receive signals thereby, Thus, the device to be described hereinafter represents a departure from those similar in structure which are used solely for selective code signal receiving; see U.S. Patents 2,575,198; 2,595,614; and 2,947,974. The device may also be used for selective code signal receiving, omitting the sending function, and thus functions similarly but, in certain respects, in a superior fashion, to the structures set forth in the aforementioned United States patents.

It is an object of this invention to provide a selective signal receiving and sending device.

It is a further object of this invention to provide an electro-mechanical selective signal device which incorporates driving means for the code plate thereof which operates to drive the code plate in a uniform manner.

Other objects and advantages of this invention, if not specifically set forth, will become apparent from the description which follows.

In the drawings:

FIGURE l is a perspective view of a preferred embodiment of the present invention.

'FIGURE 2 is a partially sectional, side elevation View of the structure of FIGURE l taken generally from the opposite side of the device shown in FIGURE l.

FIGURE 3 is a plan view of the structure of this invention with the code plate partially broken away.

Cil

3,172,099 Patented Mar. 2, 1965 P. ice

FIGURE 4 is a plan view similar to FIGURE 3 with additional parts removed whereby to reveal further the interior structure.

FIGURES 5-8 are schematic representations of the relationships of various of the moving parts at different stages during the operation of the device.

FIGURE 9 is a partial, sectional side elevation showing the relationship of various of the moving parts at one stage during the operation of the device.

yFICirURl-. 10 is a diagram of one form of the wiring arrangement and connections which make possible the use of the device both as a signal receiver-decoder and as a signal sender or generator,

`FIGURE lll is a diagram of a structure which incorporates certain of the components of EFIGURE 10 and which shows an electronic means for performing certain functions performed mechanically by elements shown in FIGURE 110.

Fundamental to both the encoding and decoding schemes is the advance or forward movement of a memory element from one bit or pulse position to the next by means of a drive unit controlled by the incoming pulses whether from a communication channel or from a pulse generator, so that an incoming signal may be compared bit by bit, pulse by pulse with the code stored in the memory element. When used as a decoder coincidence between the incoming signal and the code stored in the memory element causes the memory element to be placed `in a position which will produce an alarm signal. When used as an encoder the memory element acts as a control element controlling the count sensor which controls the time delay unit, thereby controlling the pulse generator which sends coded signals into the communication channel.

When these elements are connected and used as a decoding selector, the following actions take place: provided that the conditions of pulse rate, pulse amplitude, percent mark time, etc., are within tolerance limits the coded pulse selector is discriminatory only in the sense that it counts pulses in the order which they come in and compares the individual digit count to the digit count of a code which has been preset into the memory. lIf each digit or consecutive train of pulses coming into the selector is identical to the digits of a code stored in the memory, the selector will code and provide an alarm signal by making an electrical contact but not if any digit in the incoming signal is not identical in pulse count and digital position to the code which is set into the memory element.

If any stored digit at a given position in the memory element does not coincide with the incoming digits advancement of the memory element is stopped, and the memory element is moved to the start of the first digit position which will in effect reject the incoming signal by precluding full advancement of the memory element. During the train of pulses the memory element is allowed to move only unidirectionally, the drive unit providing the forward motion and the latch unit preventing retrograde motion of the memory element. Either of two conditions will cause the memory element to reset, and thus reject the coded signal: (l) When the pulse train on any given digit of an incoming signal ceases before complete advancement of the memory element to the next digit position. This is known as undercount- (2) Continuation of the pulse train by one or more bit positions beyond the next digit position; this is knownas overcount.

Condition (2) requires that some means be provided to prevent the memory element from advancing more than one bit position beyond the next digit position to preclude the possibility of moving the memory element nec'trn with the decoder.

.3 to the digit position next in line. This is known as overcount protection.

In the device to be described in greater detail hereinafter, there is provided a movable control plate and propelling means for the control plate. The control plate carries two or more preset pins, and plate and pins toge'ther constitute the aforementioned memory element. The propelling means incorporates a pawl for engaging lthe control plate and driving the plate in small uniform increments and a pulsing armature operatively associated with the pawl whereby at the outset of each pulse of the pulsing armature, the pawl is withdrawn from engagement with the control plate and released for reen'gagement with the control plate at the termination of the pulse. Advancement of the control plate is assured by the provision of a resilient means which urges the pulsing armature to a normal position on termination of the pulse, the resilient means moving th-e pulsing armature a sutlicient distance to allow the pawl to advance the control plate one of said uniform increments. As in the devices described in the above-mentioned patents, means are provided for assuring that the device is receptive to a predetermined code signal composed of a series of integers and at the completion of the predetermined vseries 'of integers, a contact element carried by the control plate permits a circuit to be closed whereby to operate an electrical switch or mechanism at a remote station to energize a visual or oral signal or to perform some function.

To transform the decoder outlined above to an encoder, a pulse generator and time delay unit or current interruptor are required in addition to the elements of the decoder. The time delay unit or interrupter means is in a position to be actuated by the memory unit and in turn governs the action of the pulse generator which feeds pulses to 'the drive unit. When the unit is used as an encoder, the

pulse generator actuates the drive unit which advances the memory elementto a tirst advanced position at which point the memory unit causes the interrupter means to be actuated, thus inhibiting the pulse generator during a specitied time delay. In one preferred arrangement of these devices, 'the' time lapse is sufficient to allow all decoding selectors which are in receipt of a signal from the encoder to go through the time delay cycle described in con- The memory unit also controis the position of a latch or pawl which holds the ineinory element in position throughout the time period required by the interrupter means. Following this, the

.pulse 'generator is no longer inhibited and proceeds to drive the memory element through the bits of the second digit. This procedure Vis repeated until the complete train of pulses has been produced at which time the alarm 'signal emanating from the element may be used to reset the memory element by releasing the latch.

, In somewhat 'greater detail, when used as an encoder,

"the device incorporates a movable control element or plate 'carrying two or more pins, the plate and pins constituting the memory unit, propelling means for said control element, means for engaging the propelling means `with the control element and disengaging the propelling means therefrom and means for causing the propelling 'means to pulse or reciprocate in rapid succession whereby *to provide means for advancing the control clement in uniform increments from a normal position to a first advanc'ed pos1t1on 1n response to a series of pulses by said propelling means. -A member is carried by the movable control element at a point corresponding to the first ad- V`va`ircedfposition- A slow-releasing element operatively as- `soc1atedW1th the propelling means and responsive once to a series of pulses by the propelling means and releasing upon the completion of the series of pulses is provided, as in the devices vdescribed in the aforementioned patents. Alsovprovided is a blocking element carried by the slow- :releasing element, the vblocking means obstructing the path of the member carried by the control element and Cil preventing further advancement 0f the control element when the slow-releasing element is actuated and moving out of the path of the said member upon a partial release movement of said slow-releasing element. Critical to the use of this device as a code sender is the provision of interrupter means operatively associated with the blocking element and so mounted as to be actuated by the blocking element when the member carried by the control element contacts the blocking element, the interrupter means being operatively associated with the propelling 'means whereby to terminate the action of the propelling means, complete a pulse group and partially release the slow-releasing element when the interrupter means is actuated. The interruptor means permits the resumption of the pulsing by the propelling means following the partial release of the slow-releasing element.

Referring now to the drawings wherein like characters refer to like parts throughout, there is shown a control element `or plate 12 having a series of equidistantly spaced notches 14 about the periphery thereof. The plate is mounted about a hub in (see FIGURE 2) having a collar 1S thereon. The hub 16 is loosely mounted for rotation about sleeve 20 which is supported by spindle 22, in turn tapped for receipt of screw 24 which serves as means for holding the sleeve 20 thereon. Circular washer 2e is held in place by the split washer 23 which retains hub lo in place about the sleeve Ztl. Plate 30 is fixed about the lower portion of hub 16 and will not rotate relative thereto while spindle 22 is fixed to plate 32 by means of cooperating nange 33 and head 34. A nylon stud 36 passes through plates 3i) and 32 so as to prevent relative rotation thereof. Plate 3G is provided with an upstanding flange 38 which cooperates with depending pin de, in turn, secured on the underside of the code plate 12 to prevent clockwise movement of the code plate l2 beyond a predetermined point.

Channel-shaped collar 42 fric-tionally engages hub i6. The outstanding flanges of the collar grasp and hold-the innermost portion `of spiral spring 44 in place. The other end of the spring is crimped about pin 45, in turn mounted on plate 30 (see FlGURE 3). Thus, the spring tends to rotate the code plate l2 in a clockwise direction until rotation is stopped through the action of flange 38 and pin 4G.

Plate 32 is secured to the frame of the device by stud 36, aforementioned, and by means of an additional stud 46 (see FIGURE 3). As may Vbest be seen in FlGURE 4, the

'frame consists of a pair of L-shaped steel members 4S and L-shaped member 5t) is provided with bracketsk 56 and 57, each of which serve to support additional parts to be described hereinafter. Piv-otally secured to Plate 32 by means of stud 46 is the bracket-mounted pawl 60. T he pawl is urged inwardly by spring e2 which, in turn, is hooked to an edge of plate 32. The pawl thus normally rests in one of the notches 14 of code plate l2.

Secured to the short arm of L-shaped frame member 5@ is stud 6e which supports inductor 66 and nylon spacer 67. In like fashion, stud 68 is secured to frame member t3 and supports inductor '70 thereon. Inductor 'tl is provided with means for slowing the collapse of magnetic ilux when the flow of current is ceased therethrough, a copper slug 72 and/ or a coil 73 being suitable means of achieving this (see FIGURE 10). Pivoted to brackets 54 and 55 by means of nylon pin 36 is armature '76 which preferably has riveted thereto a brass facing 'plate 78. To the opposite side of the Vdevice is pivoted slow-releasing armature 8@ by means of pin 46 passing through holes in brackets 56 and 57. Spring S2 is secured at one end thereof adjacent bracket 55 and to the slow-moving armature at the other whereby to urge the slow-moving armature away from the inductor 7).

Secured to one side of armature 76 is the bracketed yoke member 84, one linger of which is positioned on either side of the ilexible actuator 86 of the snap action switch 8S, in turn bracketed to plate 32. A suitable commercially available switch is the model No. S-36-01A switch manufactured by the Cherry Electric Products Corporation of Highland Park, Illinois. As the actuator 86 is moved from side to side, the eXible copper supports 90 are snapped from one side to the other through the action of springs 92 with the result that movable contact members 94 alternately touch the opposed contact points which are fixed in position directly adjacent thereto. Armature 76 supports a bracket 95 on the opposite end thereof through which passes pin 96 about which pivots yoke 9S which in turn supports driving pawl 100. Spring 102 is crimped about pin 96 at one end and crimped at the other end thereof about plate 32 (see FIGURES 2 and 3) and provides sufficient tension to return the armature 76 to a rest position when current flow through inductor 66 is terminated and the field thereof collapses. The driving pawl 100, thus, advances the code plate 12 the width of one notch 14 immediately following collapse of the magnetic flux in the inductor 66, the plate being driven through the reaction of spring 102. The pawl is withdrawn from the plate when current is first supplied to the inductor. The result is a more uniform driving action than has been possible with the structures of the aforementioned patents in that the spring can be depended upon to move the pawl in a uniform manner, independent of current fluctuations through the windings of inductor 66.

Armature S0 also supports a number of moving parts.

vIts bracket 104 supports one end of rod 106. The opposite Vflows through coil 66, causing armature 76 to pivot,

armature 80 will also be pivoted toward coil 70 to some extent.

Contact arm 110, having contact pin 112 thereon, is pivoted about pivot point 114. Screws 116 are grounded to the armature and hold the arm 110 to U-shaped bracket 118, in turn pivoted to plate 32 by means of stud 114. The bracket 118 is loosely secured at the opposite end thereof to ange 120 of the slow-releasing armature 80 by means of sliding pin 122. Action of the slow-releasing armature thus causes U-shaped bracket 118 to pivot about stud 114 and arm 110 is thus similarly pivoted. The arm 110 is insulated from bracket 118 by means of fiber insulators 124 and is also insulated from screws 116. A soldering lug 126 is positioned between one of the ber insulators and the surface of arm 110.

Spring 123 is crimped at one end about pin 122 and passes directly above plate 34, thereafter to be crimped about the sleeve 130 which is mounted co-axially about a driving pawl 100. The spring serves to insure that the driving pawl is normally maintained in engagement with one of the notches 14 of the code plate 12.

Secured to the slow-moving armature 80 by means of screws 132 are the spring metal straps 134 and 135, the

latter terminating in soldering lug 136. Fiber insulators 138 and 140 maintain the straps electrically insu-lated from one another.l Strap 134 is grounded to the armature 80 by means of screws 132 while strap 135 is wired in series with the windings of Athe armatures through lug 136. The straps 134 and 135 are each provided with electrical contacts designated `142 and 144 respectively. The exterior strap 134 has Isecured thereto an upstanding bracket 146 having a non-conductive cushion 143 mounted on the upper end thereof which, when the slowrelease armature 80 is in a fully released position, bears 4against the lateral face of contact-supporting arm 110.

hereinafter.

the result that the cushion l148 moves out of contact with the face of the supporting arm and the contacts 142 and 144 are allowed to close. In the absence of the cushion 148, contacts 142 and 144 would remain closed immediately following reset of the code wheel 12 with the result .that the device would continually repeat the predesignated code signal as long as current continued to be supplied to the coils.

The horizontal extension 150 is supported by strap 134 and cooperates with other portions of the apparatus, lto be described hereinafter.

Attention is now directed to FIGURE 4 which is similar to FIGURE 3 but, in addition, shows the internal structure of the device, code wheel 12, plates 30 and 34 being removed. Pin 152 is supported lby a horizontal bracket 154 which is mounted midway between the ends of yarmature 80. Secured by means of pin v152 to horizontal bracket 154 is plate 156 having an upstanding ear 158 thereon. A second upstanding ear 160 serves as the means for contacting pawl 60 (see FIGURE 3) whereby to cause retraction thereof when the slowreleasing armature 80 returns to= its normal position. Pivoted to plate 156 by means of pin 162 is a second plate 164 having an arcuate arm thereon from which eX- tends an upright blocking element or flag 166. Pin 162 also passes through the other end of plate 156 and with pin 152 prevents movement of plate 156 relative to plate 154.

Coil spring 167 is secured at either end thereof to the fingers of plates 156 and 164 so as to urge plate 164 in a clockwise direction relative to plate 156 until stopped vby the action of pin 152, as seen in FIGURE 4. Blocking element 166 is notched at 168 on the edge thereof nearest the ear 158, for reasons which will be set forth The iiag 166 is positioned closely adjacent the end of flange 150 (see FIGURE 3) so that when plate 164 is rotated in a counterclockwise direction, the ag 166 will contact the end of the ange 150 and cause contacts 142 and 144 .to be opened and current flow therethrough terminated. Plate 164 is provided with a radial extension 169 which is closely adjacent a downwardly depending portion of the pawl 100 and it may be seen that when the plate 164 is rotated in a counterclockwise direction, the .pawl will be moved away from one of the notches 14 of the plate 12 against the resistance of spring 128.

The code wheel 12 is provided with one or more down- 'wardly depend-ing pins 170 (see 4FIGURE l) which represent -the lowermost extremities of L-shaped coding elements 172. A plurality of holes 173 are provided about the periphery of the code wheel 112 whereby to permit the re-positioning of the individual code pins so as to make possible a selection of a wide variety of codes, precisely as described in Patent 2,947,974. There is also provided a contact pin 174 having an upstanding portion 176 and a downwardly depen-ding portion 178, again similar to the structure shown in the aforementioned patent. The location of this contact pin may also be changed at will so as to provide a variety of terminal digits. One end of pin 174 and pin-s `172 are forced between collar 16 and the surface of code plate 12 so as to retain the pins -frictionally in the desired positions. The

blocking element or `flag 166 is so positioned relative to `the downwardly depending pins 170 and .178 that the iag 166 will be contacted thereby as the code wheel is rotated. The notch 168 is of suflicient length to allow pins 170 .to pass immediately after contact thereof with Hag 166, but, as shown in FIGURE 9, downwardly depending pin 178 is longer than downwardly depending pin 170 for reasons which will be described hereinafter.

Suitable adjustment screws, 180, are provided for purposes of adjusting the throw of both the slow-releasing armature 80 and the pulsing armature 76.

irrespective of whether the device lis used as an electrical signal decoder or as a creator of a coded electrical signal `which may be transmitted to a remote decoder similar to that hereinbefore described, the device is adjusted so that the slow-releasing arma-ture will not release between cycles Awithin a code group but will release between code groups. Thus, the length of each pulse is not critical but the space between pulses within a code group must not exceed the retention time of the slow-releasing arma-ture, while the space ybetween code groups is not critica-l so long as it is long enuogh to allow the slowreleasing armature to assume a partially released position, as will be described hereinafter.

When used as a decoder, the snap action switch Sti and the assembly consisting of the 4second pair of contacts 142 and 144 attached to the flexible supports therefor are not used. A code is selected as, for example, the .5-5-67 shown in FIGURE 1 and the armatures 76 and 80 are in the rest position of FIGURE l() and the code wheel 12 is in a fully clockwise position, as seen in FIGURE 1. When used as a decoder, switches A, B, `C and D are open and switch E is closed, a suitable solenoid of conventional construction being used to operate the switches. The solenoid controlling these switches also may control switch F which, when in the position shown, will supply current to lamp 133 when the pro-per code signal has been received. An open circuit telephone dial of the type shown in FIGURE 7 of the Stickel Patent 2,575,198, and here indentified as 19t) is dialed to the digit 5. Battery 1%2 serves as a source of direct current and five discrete current pulses are applied to inductor 66 with the result that the armature 76 is pulsed ve times. Inductor 70 is wired in series with inductor 66 and, therefore, the slow-moving armature S@ is also Aattracted to one end of the coil 7?. coil 70 decays at a slower rate than that of coil 6e following cessation of current flow due to the action of slug 72 and/or coil 73 and capacitor 74. Thus, armature remains continually in a closed positie-n as armature 76 pulses the prescribed number of times. After each pulse, pawl is urged into one of the notches 14 so as to prevent the code wheel 12 from being reset. Following receipt of four pulses, the relationship of certain of the moving parts will be that shown in FIGURE 5 with the lowermost portion ot pin 170 approaching the blocking member or flag 1de. On receipt of the fifth pulse, the blocking member is swung counterclockwise about pivot point 162, as shown in FIGURE 6. Cessation of the rapid series of pulses allows slow-moving armature 80 to retract somewhat to a partially released position with the result that blocking member 166 is swung out of the path of pin 176. Upstanding ear 158 then contacts the pin 17h, as shown in FIGURE 7, so as to prevent the slow-releasing armature 80 from returning fully to its original rest position, the upstanding ear 153 being, as aforementioned, supported by plate 156, the action of which is also dependent upon slow-releasing armature 8h. Had a signal of less than ve been received, contact between pin 170 and ear 158 would not have been achieved (see FIGURE 5) and the slow-releasing armature would have returned to its original rest position, thereby retracting pawl 60 from one of notches 14 and allowing code wheel 12 to be reset under the influence of spring 44. Had a larger number than five been received, passage of pin 170 would have been blocked by the action of blocking member or flag 166 which, at no time, would have had an opportunity to pivotto one side through partial release of armature titl. Thus, the blocking member 166 would have prevented the movement of the pin 176 more than a single notch beyond the point represented by the digit 5 but, at the same time, the pin 170 would have been carried beyond ear 15S so that, on release of slowreleasing armature Sil, pin 170 and ear 158 would not have been brought into contact, the slowlreleasing armature would have been fully returned to a rest position and pawl 60 would have been swung from between the teeth of the code wheel, in the fashion de- The flux of 's scribed above. From this first advanced position, repre- :sented by the digit 5, the additional predetermined digits are dialed, one of the digits representing each position of successive code pins 170 and, finally, of contact pin 174. As shown in FIGURE l, the device here represented requires the digit 7 to complete the code. Downwardly `depending pin 178 advances and contacts the blocking member 168 in the same manner as described above with respect to the pins 170. However, on partial release of the slow-moving armature following the digit 7, the contact pin 112 supported by arm 1.16, in turn dependent upon the movement of the slow-releasing armature 80, is brought into direct Contact with the upstanding portion 2176 of the contact pin 174. This condition is depicted in FIGURES 8 and 9. The circuit would thus be completed from the soldering lug 126, through arm 110, pin 112, pin 176 and finally through the body of the decoder to screws 116. As shown `in FIGURE 10, current'will then be supplied to lamp 188 and a signal made available for the operation of one or more switches or other mechanisms.

When used as a code sender, the circuit incorporating the telephone dial remains open (switch E is open) and switches A, B, C, D and F vare closed by the action of the solenoid. The momentary manual closing of switch 196 rwill then allow current to flow from battery 198 through switch C and through one half of the snap action switch $8 to inductor 66. Current also passes through the windings of coil 7b and the pulsing and slow-releasing armatures are attracted to their respective inductors in the manner described above. However, it will be seen that contacts 94 will be opened by the action of the pulsing armature 76 resulting in the decay of the flux of inductor 66. The collapse, however, is only momentary as the action of spring 162 is to return pulsing armature 76 again to the position shown in FIGURE 10 with the result that current is again supplied inductor 66. Throughout this time, slow-releasing armature remains attracted to the inductor 70 through the action of copper slug 72 or through the combined action of coil 73, capacitor 74 and rectifier 201). Rectifier 200 insures that current will not flow back into inductor 66 simultaneously. Throughout the time preceding the completion of a preselected number of pulses, e.g. five, contacts 142 and 144 thus remain closed, as shown in FIGURE 5. Thus, the current is allowed to flow through the inductors, strap 13S, contact 144, contact 142 and strap 134 without interruption, except to the extent that such interruption is due to the action of the snap action switch 88. However, when the preselected number of pulses representing a first digit of a code signal have been completed, as shown in FIGURE 6, the depending portion of pin 170 rotates blocking element or flag 166 in a counterclockwise direction to contact the adjacent portion of extension thereby to open contacts 142 and 144. This interrupts the flow of current through the device, the slow-releasing armature partially returns to its original position and by rotating in a counterclockwise manner, as shown in FIGURE7, pernnts contacts 142 and 144- again to be closed and the blocking element 166 to be moved radially and out of the path of pin 17d. Each of the contact makes will result in a pulse being transmitted through switch B to terminal 201 and each of the contact breaks will result 1n a pulse passing through switch A to terminal 202. The signal at terminal 202 is particularly suited to telegraph circuits while the signal at terminal 201 may be used to actuate or key various kinds of communications or control systems.

Returning now to FIGURE 7, it will be seen that the device will continue to advance the code wheel one notch at a time until the second of the pins 17@ is encountered, with the sequence of events pictured in FIGURES 5-7 then being repeated. The sequence is repeated for the third pin and finally repeated with respect to the contact pin 176 which again is brought into contact with pin 112. Contact of these two pins results in a single additional pulse which steps the code wheel one additional notch to a position such that neither cooperating pins 112 and 176 nor cooperating pins 158 and 178 may contact one another with the result that the slow-releasing armature, in the absence of ux to attract it to inductor 70, returns to its original rest position and the code wheel 12 is reset under the action of spring 44. Following the completion of an integer signal composed of a series of pulse groups followed by a single reset pulse, the code wheel 12 will remain in a reset position until switch 196 is again closed or, alternatively, contacts 142 and 144 closed manually.

It will be noted from FIGURE 9 that the final downwardly depending pin 178 is somewhat longer than intermediate pins 170. This is necessary to assure that contacts 142 and 144 will remain open following completion of the digital code signal and immediately following the one additional reset pulse and so as to prevent the depending pin 178 from ever passing the blocking flag 166. Were pin 178 the same length as pins 170, the code wheel would continue to be advanced without further interruption immediately after pin 178 had passed the blocking flag 166. For this reason, the notch 168 in flag 166 is of sufficient depth to allow for passage of pins 170 when the flag has been pivoted, as shown in FIGURE 7, but is of an insufficient depth to allow for the passage of pin 178 at any time.

Diagrammatic FIGURE 11 illustrates the manner in which the snap action switch 88 may be replaced with transistorized circuitry for providing the necessary pulses. In brief, switching transistor 300, when actuated, provides a coded output signal at terminal 301 similar to the coded signal provided at terminal 201 of FIGURE l0.

In greater detail, to initiate code sending, a momentary positive voltage is applied to the terminal 302 which actuates relay 304. This relay is held in an actuated position by positive battery through contacts 306 and 307 When the code plate 12 is in the initial or rest position, the contacts 142 and 144 are open. Thus, when relay 304 is actuated, contacts 307 and 308 are opened, removing resistor 310, suitably 4,700 ohms, from positive battery. This action causes the squaring circuit, consisting of PNP transistors 312 and 314 (suitably 2Nl414) together with their associated resistors to emit a sharp pulse through capacitor 316, suitably 0.1 microfarad, into the constant pulse width trigger circuit consisting of PNP type transistors 318 and 300, both suitably 2Nl4l4 transistors which, with their associated resistors, provide a pulse of constant predetermined width time (determined by resistor 320, here suitably 6,800 ohms, and capacitor 322, here suitably 4.7 micro-farads) to pulsing relay 324. Pulsing relay 324 actuates contact 326, which, in turn, provides a constant predetermined pulse width to inductors 66 and 70 and also provides a constant predetermined pulse width to point 328 through contacts 329 and 330. The pulse provided to the inductors 66 and 70 initiates the code plate advancing action previously described, while the same pulse provided Vto point 328 brings point 328 to negative battery. Simultaneously, contacts 142 and 144 are closed, providing positive battery to point 332, preparing ,the squaring circuit for providing trigger pulses to `the trigger circuits. At the termination of the constant width pulse from the trigger circuit, contacts 3.26 open, allowing the voltage at point 328 to drift away from the negative battery voltagain provides current to relay 324, causing contacts 326 to close as before, which causes inductor 66 to actuate the 10 mechanism and which again brings point 328 to negative battery. When the point 328 is again brought to negative battery, the conduction states of .transistors 312 and 314 are reversed, which puts another trigger pulse through capacitor 316 to the trigger circuit. The second pulse to the trigger circuit occurs virtually instantaneously on receipt of the pulse at relay 324. Hence, while the second pulse does not reactuate the trigger circuit, the predetermined pulse width is virtually identical to the width of the first pulse provided by the trigger circuit after the iirst pulse in any digit. Thus, for the first pulse in any digit, the conduction states of transistors 312 and 314 change only once while, for all succeeding pulses,

. as a code sender.

inductor 76.

the conduction states change twice per pulse.

When the preselected number of pulses representing a first digit of a code signal have been completed, the mechanism action as previously described takes place, causing contacts 142 and 144 to open, which removes point 332 from positive battery. On termination of the last pulse of the digit, contacts 326 open. But since point 332 is not at positive battery, point 328 tends to remain at negative battery and the squaring circuit is inhibited from providing a sharp trigger pulse to the trigger circuit. Inductor 70 then fails to attract the slow-releasing armature 80. When the slow-releasing armature reaches its rest position, as previously described, contacts 142 and 144 again close, bringing positive battery to point 332 which again initiates the pulsing action. In this fashion, the complete sequence of digits is pulsed and appears as a coded output signal at point 301. When the total sequence of digits is completed, pin 176 makes contact with pin 112 carried by the slow-release armature which provides positive battery to point 336. This has the effect of removing voltage from relay 304, causing it to drop out, which, in turn, causes pulsing to cease by opening contacts 306/307 and 329/330, which prevents actuation of the squaring circuit.

In addition to the components described above, the circuit shown in FIGURE 11 incorporates resistor 338, suitably 100,000 ohms; resistor 340, 342 and 344, each suitably 2,200 ohms; resistor 346, suitably 680 ohms; resistors 348 and 350 and 352, each suitably 1000 ohms; resistor 354, suitably 4,700 ohms; resistor 356, suitably 680 ohms; and resistor 358, suitably 6,800 ohms. Finally, resistor 360 may be ohms. The circuit also incorporates diodes 362, 364, 366 and 368, each suitably DI-52 (Diodes Inc. No. 52).

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed `as are indicated in the appending claims.

For example,` a single inductor might be used, as described inPatent 2,947,974, and obviously the wiring could be Isimplified to permit the use of the device only as a code selector for receiving purposes or, alternatively, Also, means other than snap action switch 88 could be used to supply a series of pulses to Finally, the reaction drive mechanism de scribed for the pulsing armature might be replaced with the direct drive mechanism shown in the aforementioned patents, but as pointed out earlier, the reaction drive mechanism provides greater uniformity of and dependability 4of operation.

I claim:

1. A selective code signal sending device comprising: in combination, a movable control element; propelling means for said control element; means for engaging said propelling means with said control element and disengaging said propelling means therefrom whereby to provide means for advancing said control element in uniform increments from a normal position to a first advanced position vin response to a series of pulses by the said propelling means; a member carried by said movable control element at a point corresponding to said first advanced position; a slow-releasing element operatively associated with said propelling means and responsive once toa series of pulses by said propelling means and releasing upon completion of said series of pulses; a blocking element carried by said slow-releasing element, said blocking element obstructing the path of said member and preventing further advancement of said control element when said slow-releasing element is actuated and moving out of the path of said member upon a partial release movement of the said slow-releasing element; interrupter means operatively associated with said blocking element and so mounted as to be actuated by said blocking element when said member contacts said blocking element, said interrupter means being operatively associated With said propelling means whereby to terminate the pulsing action of the said propelling means and thereby partially release said slow-releasing element when said interrupter means is actuated, said interrupter means permitting the resumption of pulsing by said propelling means following said partial release of said slow-releasing element; and pawl means releasable by actuation of the said slow-releasing element to engage said movable control element and prevent retrogade movement of the said control element except when said slow-releasing element is yfully released.

2. A selective code signal sending devicecomprising: in combination, a movable control element normally biased in the first direction; propelling means for said control element; means for engaging said propelling means with said control element and .disengaging said propelling ,means therefrom whereby to provide means for advancing said control element in uniform increments from a normal position to a first advanced position, said propelling means including a pulsing armature and an nductor positioned adjacent thereto whereby to provide means for pulsing said armature; means for supplying current to said nductor; rst interrupter means for interrupting the liow of said current to -said nductor, Said interrupter means being operatively associated with said pulsing armature whereby when said armature is pulsed, said current is interrupted momentarily; a member carried by said movable control element at a point corresponding to said iirst advanced position; a slow-releasing element operatively associated with said propelling means responsive once to a series of electrical pulses applied to said nductor and releasing upon the completion of said series of electrical pulses; a blocking element carried by said slow-releasing element, said blocking element obstructing the .path of said member and preventing further advancement of said control velement when said slow-releasing element is actuated and moving out of thepath of said member upon a partial release movement of the said slow-releasin g element; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by said blocking element when said member contacts said blocking element, said second interrupter means terminating the llow of current to said nductor whereby to terminate the pulsing of said armature and partially release said slow-releasing element when said second interrupter means is actuated, said second interrupter means permitting the resumption of current flow to said nductor following said partial release of said slow-releasing element; and pawl means releasable by actuation of the said slow-releasing element to engage said movable control element and prevent retrograde movement of the said control element except when said slow-releasing element is fully released.

3. A selective code signal sending device comprising: in combination, a movable control element normally biased in the rst direction; propelling means for said control element; means for engaging said propelling means with said control element and disengaging `said propelling means therefrom whereby to provide means for advancing said control element in uniformi increments from ,a normal position to a lirst vadvanced position, said propelling means including a pulsing armature' and a lirst nductor positioned adjacent thereto whereby to provide means for pulsing said armature; means for supplying current to said rst nductor; lirst interrupter means for interrupting the flow of said current to said first nductor, said interrupter means being operatively associated with said pulsing armature whereby when said `armature lis pulsed, said current is interrupted momentarily; a member carried by said movable control element at a point corresponding to said first advanced position; a second nductor positioned adjacent said rst nductor and means for supplying current thereto; a slow-releasing armature operatively associated with said Second nductor, Said second nductor being provided with means for delaying the collapse of magnetic tlux when current flow therethrough is terminated; a blocking element carried by said slow-releasing armature, said blocking element obstructing the path of said member and preventing further advancement of said control element when said slow-releasing armature is actuated and moving `out of the path of said member upon a partial release movement of said slowreleasing armature; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by said blocking element when said member contacts said blocking element, said second interrupter means terminating the iiow of current to said inductors whereby lto terminate the pulsing of said first armature and partially release said slow-releasing armature when said second interrupter means is actuated, said second interrupter means permitting the resumption of pulsing by said pulsing armature following said partial release of said slow-releasing armature.

4. An electric, selective code signal sending device comprising: in combination, a circular, rotatably mounted, biased control plate having a series of notches evenly spaced about the periphery thereof; a pawl for engaging said notches and driving the said control plate solely in notch-wide increments; a 'pulsing armature for driving the said pawl whereby to provide means for engaging the said pawl with the said notches to advance said control plate from a normal position to a predetermined iirst advanced position; a irst nductor positioned to attract the said pulsing armature when current is passed therethrough; rst current interrupter means wired in series with the said first nductor, said interrupter means terminating the flow of current to said lirst nductor with each pulse of the said pulsing armature and re-establishing current flow following de-energization of said lirst nductor; a member carried by said control plate at a point corresponding to a irst advanced position; a second nductor positioned adjacent said irst nductor, said second nductor having means operatively associated therewith for delaying linx decay in said second nductor following termination of current llow therethrough; a slowreleasing armature operatively associated 'with said second nductor; a blocking element carried by said slowreleasing armature, said blocking element obstructing the path of said member and preventing further advancement of said control plate when said slow-releasing armature is actuated and moving out of the path of said member upon a partial release movement of said slow-releasing armature; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by said blocking element when said member contacts said blocking element, said second interrupter means terminating the flow of current to said inductors whereby to terminate the pulsing of said first armature and partially release said slow-releasing armature when said second interrupter means is actuated, said second interrupter means permitting the resumption of pulsing by said pulsing armature following said partial release of said slow-releasing armature.

5. An electric, selective code signal sending .device comprising: in combination, a circular, rotatably mounted, biased control plate having a series of notches even- 13 ly spaced about the periphery thereof; a pawl for engaging said notches and driving the said control plate solely innotch-wide increments; a pulsing armature for driving the said pawl whereby to provide means for engaging the said pawl with the said notches to advance said control plate from -a normal position to a predetermined first advanced position; a first inductor positioned to attract the said pulsing armature when current is passed therethrough; a fir-st current interrupter means wired in series with the said first inductor, said interrupter means terminating the flow of current to said first inductor with each pulse of the said pulsing armature and re-establishing current ow following de-energization of said first inductor; a member carried by said control plate at a point corresponding to a first advanced position; a second inductor positioned adjacent said first inductor, said second inductor having means operatively associated therewith for delaying fiux decay in said second inductor following termination of current flow therethrough; a slow-releasing armature operatively associated with said second inductor; a blocking element carried by said slow-releasing armature, said blocking element obstructing the path of said member and preventing further advancement of said control plate when said slow-releasing armature is actuated and moving out of the path of said member upon a partial release movement of said slow-releasing armature; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by `said blocking element when said member contacts said blocking element, said second interrupter means terminating the flow of current to said inductors whereby to terminate the pulsing of said first armature and partially release said slow-releasing armature when said second interrupter means is actuated, said second interrupter means permitting the resumption of pulsing by said pulsing armature following said partial release of said slow-releasing armature; and a contact member carried by saidl control plate and a second contact member fixed generally in the path of said first contact member, said contact members being so positioned that whensaid control plate is at a farther advanced position, said Contact members can be caused to contact one another whereby to vcomplete an electric circuit, said circuit including the said first inductor whereby completion of said circuit causes the saidpulsing armature to l advance said code plate an additional notch-wide incre- I ed, biased control plate having a'series of notches evenly spaced about the periphery thereof; a pawl for engaging said notches and driving the said control plate vsolely in notch-wide increments; a pulsing armature for 'driving thesaid pawl whereby to provide means for engaging the said pawl with the said notches to advance said control plate from a normal position to a predetermined first advanced position; a first inductor positioned to attract the said pulsing armature when current is passed therethrough; first current interrupter means wired in series with the said first inductor, said interrupter means terminating the ow of current to said first inductor with each pulse of the said pulsing armature and re-establishing current fiow following de-energization of said first inductor; a member carried by said control plate at a point corresponding to a first advanced position; a second inductor positioned adjacent said first inductor, said second inductor having means operatively associated therewith for delaying fiux decay in said second inductor following termination of current flow therethrough; a slowreleasing armature operatively associated with said second inductor; a blocking element carried by said slowreleasing armature, said blocking element obstructing the path of said member and preventing further advancement of said control plate when said slow-'releasing armature is actuated and moving out of the path of said member upon a partial release movement of said slow-releasing armature; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by said blocking element when said member contacts said blocking element, said second interrupter means terminating the flow of current to said inductors whereby to terminate the pulsing of said first armature and partially release said slow-releasing armature when said second interrupter means is actuated, said second interrupter means permitting the resumption of pulsing by said pulsing armature following said partial release of said slow-releasing armature; a contact member carried by said control plate and a second Contact member fixed generally in the path of said first contact member, said contact members being so positioned that when said control plate is at a farther advanced position, said contact members can be caused to contact one another whereby to complete an electric circuit,V said circuit including the said first inductor whereby completion of said circuit causes the said pulsing armature to advance said code plate an additional notch-wide increment; and means secured to the said second interrupter means for actuating the said second interrupter whereby to terminate the flow of current to both inductors when the said slowreleasing armature is fully released.

7. A selective code signal sending device comprising: in combination, a moveable control element normally biased in the first direction; propelling means for said control element; means for engaging said propelling means with said control element and disengaging said propelling means therefrom whereby to provide means for advancing said control element in uniform increments from a normal position to a first advanced position, said propelling means including a pulsing armature and an inductor positioned adjacent thereto whereby to provide means for pulsing said armature; means for supplying current to said inductor; first interrupter means for interrupting the flow of said current to said inductor; said interrupter means including a snap action switch wired in series with the said means for supplying current to the first inductor, said snap action switch having means secured to the said pulsing armature for opening and closing the said snap action switch as the said pulsing armature pulses whereby to interrupt the flow of current through the said first inductor; a member carried by said movable control element at a point corresponding to said advanced position; a slow-releasing element operatively associated with said propelling means responsive once to a series of electrical pulses applied to said inductor and releasing upon the completion of said series of electrical pulses; a blocking element carried by said slow-releasing element, said blocking element obstructing the path of said member and preventing further advancement of said `control element when said slow-releasing element is actuated and moving out of the path of said member upon a partial release movement of the said slow-releasing element; second interrupter means operatively associated with said blocking element and so positioned as to be actuated by said blocking element when said member contacts said blocking element, said second interrupter means terminating the flow of current to said inductor whereby to terminate the pulsing of the said pulsing armature and partially release said slow-releasing element when said second interrupter means is actuated, said second interrupter means permitting the resumption of current flow to said inductor following said partial release of said slow-releasing element; and pawl means releasable by actuation of said slow-releasing element to engage said movable control element and prevent retrograde movement of said control element except when said slow-releasing element is fully released.

8. An electric, selective code signal sending device comprising: a circular, rotatably mounted, biased control plate having a series of notches evenly spaced about the periphery thereof; a pawl for engaging said notches and driving the said control plate solely in notch-wide in- 15 crements; a `pulsing armature operatively associated with said pawl whereby at the outset of each pulse of said pulsing armature, said pawl is withdrawn from one of said notches; resilient means urging said pulsing armature to a normal position on termination of each of said pulses whereby to engage said pawl with a notch of said control plate; said resilient means moving said pawl a sufficient distance to allow said pawl to advance said control plate a distance equal to the widthr of one notch ofthe said plate; a member carried by said control plate at a point corresponding to a first advanced position; a slow-releasing element operatively associated with said pulsing armature responsive once to a series of pulses of the said pulsing armature and releasing uponthe completion of said series of pulses; a blocking element carried by said slow-releasing element, said blocking Velement obstructing the path of said member and preventing further advancement of said control plate when said slow-releasing element is actuated and moving out of the path of said memf ber upon a partial release movement of the said slowreleasing element; interrupter means operatively associated with said blocking element and so positioned as to be actuated -by said blocking element when said member contacts said blocking element, saidinterrupter means terminating the pulsing of said pulsing armature and partially releasing said slow-releasing element when said interrupter means is actuated, said interruptor means permitting the resumption of pulsing of the said pulsing armature following partial release of the said slow-releasing element; and pawl means releasable by actuation of said slow-releasing element to engage said control ,plate and prevent retrograde movement of said control ,plate `except when said slow-releasing element is released.

9. An encoder comprising:

(a) a movable control plate mounted for movement between a rest position and a position of maximum advance and having a driving `means therefor, said driving means being capable of advancing said control in uniform increments;

(b) means generating a series of electrical pulses for actuating the said driving means in step-wise increments;

(c) atleast a pair of elements carried by the said control plate, the first element being positioned at a rst predetermined position which is a position intermediate said rest position and said maximum advanced position and the second of said elements being positioned at said maximum advanced position;

(d) interrupting means positioned adjacent said control plate in the path of said elements for contacting said irstelement to interrupt the flow ofelectrical pulses to the said driving means when the iirst of said ele- ES ments reaches the said predetermined advanced posi, tion; and

(e) means for moving the said interrupting means out of the path of the said first .element carried by the said control plate after a predetermined time interval and for deactivating said interrupting means thereby to permit the said pulses .to again be supplied to the said driving means whereby to advance said control plate in uniform increments to a point where the second of the said elements carried by the said control plate contacts the said interrupting means.

l0. An encoder comprising:

(a) a movable control plate mounted for movement between a rest position and a position of maximum advance and having a driving means therefor, said driving means being capable of advancing said control in uniform increments;

(b) means generating a series of electrical pulses for actuating the said driving means in step-wise increments;

(c) at least three elements carried by the said control plate, the i'irst two of said elements being positioned respectively at a first and a second predetermined position which are positions intermediate said rest position and said maximum advanced position and said third element being positioned at said maximum advanced position;

(d) interrupting means positioned adjacent said control plate in the pathV of said elements for contacting said first element to interrupt the flow of electrical pulses to the said driving means when the rst of said elements reaches the said predetermined advanced position; and

(e) means -for moving the said interrupting means out of the path of the said first two elements carried by the said control plate after a predetermined time interval and for deactivating the said interrupting means whereby to permit the said pulses to again be supplied to the said driving means whereby to advance said control plate in uniform increments .to a point where the third of said elements carried by said control plate contacts the said i interrupting means.

References Cited in the tile of this patent UNITED STATES PATENTS FOREIGN PATENTS 461,753 Great Britain Feb. 24, 1937 

9. AN ENCODER COMPRISING: (A) A MOVABLE CONTROL PLATE MOUNTED FOR MOVEMENT BETWEEN A REST POSITION AND A POSITION OF MAXIMUM ADVANCE AND HAVING A DRIVING MEANS THEREFOR, SAID DRIVING MEANS BEING CAPABLE OF ADVANCING SAID CONTROL IN UNIFORM INCREMENTS; (B) MEANS GENERATING A SERIES OF ELECTRICAL PULSES FOR ACTUATING THE SAID DRIVING MEANS IN STEP-WISE INCREMENTS; (C) AT LEAST A PAIR OF ELEMENTS CARRIED BY THE SAID CONTROL PLATE, THE FIRST ELEMENT BEING POSITIONED AT A FIRST PREDETERMINED POSITION WHICH IS A POSITION INTERMEDIATE SAID REST POSITION AND SAID MAXIMUM ADVANCED POSITION AND THE SECOND OF SAID ELEMENTS BEING POSITIONED AT SAID MAXIMUM ADVANCED POSITION; (D) INTERRUPTING MEANS POSITIONED ADJACENT SAID CONTROL PLATE IN THE PATH OF SAID ELEMENTS FOR CONTACTING SAID FIRST ELEMENT TO INTERRUPT THE FLOW OF ELECTRICAL PULSES TO THE SAID DRIVING MEANS WHEN THE FIRST OF SAID ELEMENTS REACHES THE SAID PREDETERMINED ADVANCED POSITION; AND (E) MEANS FOR MOVING THE SAID INTERRUPTING MEANS OUT OF THE PATH OF THE SAID FIRST ELEMENT CARRIED BY THE SAID CONTROL PLATE AFTER A PREDETERMINED TIME INTERVAL AND FOR DEACTIVATING SAID INTERRUPTING MEANS THEREBY TO PERMIT THE SAID PULSES TO AGAIN BE SUPPLIED TO THE SAID DRIVING MEANS WHEREBY TO ADVANCE SAID CONTROL PLATE IN UNIFORM INCREMENTS TO A POINT WHERE THE SECOND OF THE SAID ELEMENTS CARRIED BY THE SAID CONTROL PLATE CONTACTS THE SAID INTERRUPTING MEANS. 